1. Field of the Invention
This invention relates to fuse terminal blocks for miniature, plug-in, blade-type fuses.
2. Description of Related Art
The electrical systems of automobiles, recreational vehicles, certain types of recreational boats and other applications using direct current usually include fuses to protect the system. One type of fuse that has become popular for such applications is the miniature, plug-in, blade-type fuse. Examples of this type of fuse are illustrated in U.S. Pat. No. 3,909,767 to Williamson, et al., U.S. Pat. No. 4,224,592 to Urani, et al., and U.S. Pat. No. 4,504,016 to Viola, et al.
Various fuse terminal blocks have been developed to allow the connection of blade fuses with other components of electrical system. One feature of these fuse blocks usually is a fuse holder that allows the fuse to be connected electrically to wires leading to other components of the electrical system. Often, particularly in fuse blocks for use in automobiles, the fuse block is designed so that the fuses are arranged on the front surface of the block while the wires connected to the fuse holders exit from the rear of the fuse block. Further, the wires often are connected to the fuse holders by crimping prongs attached to the fuse holders. This combination of rear wire exiting and attachment of wires by crimping results in a fuse block that is inconvenient to service, or more particularly, difficult to modify.
In the recreational vehicle industry and similar industries, it is not uncommon for value-added manufacturers, customizers, or electrically handy owners to want to modify an electrical system. The typical automobile-type fuse terminal block does not have the features to allow for the easy and convenient modification of an electrical system. Such fuse blocks do not allow easy access to all block components, especially to the wires exiting from the back of the fuse block or to the fuse holders. Further, such fuse blocks usually are not designed to be expandable to accommodate additional or modified components. Further still, such fuse blocks usually are not designed with universal applications and installations in mind but are designed for one specific application and require specific mounts and connections for installation.
Some fuse holder assemblies feature a bus bar to allow electrical connection between a single electrical terminal and a plurality of fuse holders. In some cases, as in U.S. Pat. No. 4,432,594 to Daggett, the bus comprises a plurality of parts held together with fasteness such as rivets. In such cases, the fastness may increase the electrical resistance of the bus, causing loss of power, increased heating or failure of the bus connection. In other cases, as in U.S. Pat. No. 4,221,456 to Cairns, et al., the bus comprises a series of fuse holders that are formed by the folding of tabs extending from a strip of electrically conductive material. Fuse holders of this type are relatively difficult to manufacture, requiring multiple folding or crimping steps, and may be prone to jamming or the bending of the fuse blade.
An ideal fuse block for applications requiring modification of the fuse block after initial installation would be a fuse block made of modular components. Modular fuse carriers have been disclosed by Ballarini in U.S. Pat. No. 4,466,683 and by Bukale in U.S. Pat. No. 4,560,227; however, the fuse blocks disclosed in these patents share the common limitation of the fuse blocks of more conventional design in that there is no convenient access to the wires of fuse holders of the fuse block.